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A sample first:

1) ProductA - purchased 100 quantity at 100 each - so the base price is \$100

2) ProductA - purchased another 100 quantity but this time at \$150 each. If we combine the two, the new base price would be \$125 correct? I just know that this is correct but I don't know it was derived. Anyone here would care to show me how?

What if we have this scenario instead?

  • Purchased 100 items for \$100 each - base price is \$100
  • Again we purchased 15 items for \$150 each - the new base price for this is I don't know..

What is the new base price for this item?

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up vote 0 down vote accepted

I doubt the question will be retained, still (it is an application of Weighted Mean):

$$((p*q) + (s*t) / (q+t))$$

p - Price of item 1
q - Qty of item 1
s - Price of item 2
t - Qty of item 2


$$((100*100)+(125*100))/(100+100)) = 125$$

The solution to the second part of the question is left as an exercise to the reader. ;)

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Re the first sentence: I do think this question is on-topic. – Srivatsan Dec 20 '11 at 17:03
@Srivatsan Just thought if it was too elementary. Never Mind, in fact it is good if we address the wider audience. – check123 Dec 20 '11 at 17:06
@check123 with other words the total amount of money divided by the total amount of items, isn't it? – user21385 Dec 20 '11 at 17:28
@lef2 Well said! – check123 Dec 20 '11 at 17:30
Thanks i get this now! Answer to the second part is $106.52 – officeboi101 Dec 20 '11 at 19:27

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